There may be too many steps in the task sequence object.

So this was a new one on me.  Before you ask; no, we hadn't made any changes to our system - it just happened.  Yes - it just happened, just like I'm guessing has happened to you if you're reading this.

I fired up my SCCM console locally on my machine.  I went to edit a Task Sequence and then got this little gem:

 

Good one uh?  I then jumped on the server and tried the server console.  Still the same.

A bit of twitchy bum moments, log file seaching and a touch of Googling I found that this could be caused by MDT going; what we in the industry call; "Tits up".

Do you have MDT integrated into SCCM too?  You do?  Good - read on...

Try re-running the MDT integration as per the start menu folder location for MDT on your SCCM server and you should find things fine and dandy.

It didn't work?  Oh... Sorry - try this link here.